Okay, so I've noticed on quite a few blog posts that there are many "Wikia Contributors" who are asking the same questions over and over again, asking about Slade, Shado, and then asking/stating that characters will be appearing (when it's said they won't be)
so I'm going to write here who will be appearing later on in the series, and who is currently unconfirmed and who is not appearing.
okay, so the characters that have been CONFIRMED to be appearing later on in the series are -
"Anatoli Knyazev", leader of the Bratva and friend of Olivers, will be making a possible appearance in episodes 4 and 6
"Barry Allen" AKA: The Flash, will be making an appearance in episodes 8, 9. He will no longer be appearing in episode 20, nor will he be wearing his icon suit.
"Professor Anthony Ivo" has been confirmed to make an appearance in an Island flashback in episode 5.
"Solomon Grundy" AKA "Cyrus Gold" has been confirmed appearing in episode 7, 8, 9 and possibly 10.
characters that have UNCONFIRMED to appear (the island counts as flash backs, not present times)
"Shado" it is unknown whether she made it off of the island or died as of yet, later additions will be made here.
"Ra's Al Ghul", he has been mentioned, however he hasn't been confirmed to be making an appearance in the episodes yet.
characters that have been confirmed to NOT be making an appearance
"Bruce Wayne/Batman", will not be making an appearance, this was confirmed over twitter.
"Superman/Clark Kent", most definitely won't be making an appearance unless the writers and director change their mind.
others will be added into the blog on a later date, and changes may be made with confirmations etc.